Lubricants



Patented Aug. 21, 1945 LUBRICANTS John D. Morgan, South Orange, N. J assignor to Cities Service Oil Company, New York, N. Y., a corporation of Pennsylvania l a No Drawing. Application July 10, 1942,

Serial No. 450,417

Claims.

This invention relates to lubricants and more particularly to lubricants adaptable tor low tem-- perature lubrication.

Some types of machinery, such as the aeroplane, automobiles, trucks, ships and guns; must be lubricated when the machines are subjected to a wide range of temperatures. Such a temperature range may cover --50 F. to 200 F.

It is very desirable that the low temperature lubricant. should have a comparatively uniformv1scosity throughout the temperature range in which it operates. These lubricants should also be non-corrosive in the bearings and should be capable of carrying comparatively high bearing pressures p The primary object or the present invention is to provide a lubricant capable of efiectively lubrieating bearings at low temperatures.

Another object of the invention is to provide a method of and lubricant for lubricating bearings which will be eilective over a temperature range of from F. to 200 F.

With these and other'obiects in view the inven tlon consists in the improved lubricant and 'method of using it hereinafter described and particularly deflnedin the claims.

n I have discovered that the oxaiates, particularly the dialkyl oxalates, having comparatively high boiling points have good lubricating properties. For example, the diethyl, the dibutyl, the diisobutyl and the diisoamyl; oxalates all hell above 370 F. and have very low melting points.

Some physical properties of the above-mcn-.,

' tioned oxalates are:

- I the 4-ball testing machine of 450 1 seizing point above 1000 lbs. with 1% i any 01 the Boilln Flash M lon point, point, F. pohit, L

Diethy1oXainte 371 168 Dibutyl oxalate" 470 265. Diisobutyl oxalate" 444 1 261 Dilsoamyl oxalate" 611 241 1 Above.

The melting points of the dibutyl anddiamyloxalates have not been determined.

When the above-mentioned oxalates are tested in the 4- ball testingpmachine they have lubricating properties about better than a mineral oil parailln spindle oil having av'iscosity of 200 oxalates to spindle oil will increase its load-carry in: capacity'about 33 V3%. The viscosities oi the diethyl and dibutyl pxalates are asiollows:

Viscosities in centistolres Temperature 1 Dlethyl oxalate- Dibutyloxalate By adding totheabove-mentioned oxalates one:- of the well known extreme pressure addition agents, such as Polane, Santolube #261, and tricresyl phosphite', t'h'e load-carrying capacity or the oxalates may be increased at least 100%., For example, ethyl oxalate having a seizing point on will have a above-mentioned addition agents. "butyl oxalate which has a seizing point on the 4-ball testing machine of 400 will not seize on the testing machine when having 1% of any of the above addition agents up to and above 1000 lbs. a

The extreme pressure agent "Polanef mentioned above is chlormethyl stearate, while the Santolube #261" agent is asulfuri'zed tin salt of an alkyl phenol carboxylic acid as clearly indicated by Patents Nos. 2,197,834-5, 2,256,441 and 2,257,751, under which itis manuiactured. Other extreme pressure agents may be used, such as the gelke Patent No. 2,260,303.

A good low temperature grease can be made by incorporating a lithium soap such as lithium grease may consist essentially of a dialkyl oxalate such as dibutyl oxalate in which is incorporated aproximately.6% or lithium stearate. 'A'sui'table. grease may contain approximately 93% of dibutyl oxalate, approximately 6% of lithium stearate and approximately 1% or an extreme pressure agent.

The dialkyl'oxalates of the present invention are neutral and non-corrosive to all of the bearin: metals and alloys with which the product 100 F. The addition-ot-"3'. '2% ot'eth'yl or butyl been used. All or these oxalates colorless sulfurlzed tricresyl phosphites disclosed in En- I ster rate in cne of the dialkyl oxalates. Such a liquids and practically insoluble in water. 'In

products are, however, miscible with fatty acid soaps and the extreme pressure additiveagents.

The preferred form of the invention having been 'thus described what is claimed as new is:

1. A lubricant consisting essentially of a dialkyl oxalate having dissolved therein a small'prcportion 01' an extreme pressure agent suilicient to impart extreme pressure properties thereto.

1 2. A lubricant consisting essentially or a dialkrl 1o oxalate having dissolvedtherein approximately 1% of an extreme pressure agent. a

3. A lubricant consisting essentially or diethyl oxalate having dissolved therein a small proportion of an extreme pressure agent sufilcient to 5 impart extreme pressure properties to the lubri-' 7 cent.

4. A lubricant consisting essentially of a dibutyl oxalate having dissolved therein a small proportion. of an extreme pressure agent suflicient to 20v impart extreme pressure properties to the lubri-f cant. a v

5. A lubricant'coniprising a major portion of a dialkyl oxalate having a smallamount of a lithium soap embodied th'erein to provide astable rease.

6. A iubricant'comprlsing' a major portion pi dibutyl oxalate having a small amount of lithium stearate embodied therein to provide a stable grease.

7. A lubricant comprising a major portion oi dibutyl oxalate having approximately 6% of lithium stearate embodied'therein forming a 10. A lubricating grease comprising aproxi- I mately 6% 01' lithium stearate, the remainder'oi'.

' the grease consisting essentially or a dialhl oxalate. e m

JOHN D. MORGAN. 

